Baseline: Baseline refers to the period of 1998-2008 taken as representative of the present conditions of different variables (precipitation, evapotranspiration and water yield) in the Koshi River Basin.

Future: Future refers to the period of 2040-2050 taken as representative of the future conditions of different variables (precipitation, evapotranspiration and water yield) in the Koshi River Basin.

Scenarios: Representative concentration pathways (RCPs) are a set of four new pathways developed for the climate modeling community as a basis for long-term and near-term modeling experiments. RCPs is the innovative collaboration between integrated assessment modelers, climate modelers, terrestrial ecosystem modelers and emission inventory experts. The RCPs covers a period of 1850-2100 and the radiative forcing values of 2.6, 4.5, 6 and 8.5 W/m2. The climate scenarios selected for the study are RCP4.5, one of the medium stabilizing scenario and RCP8.5, a very high baseline emission scenario. Each RCP comprises of Four Global Circulation Models (GCMs).

Ensemble: A single prediction of the most likely future will have a high degree of uncertainty. Therefore, an ensemble of predictions from the downscaled GCMs are used to produce a range of value encompassing the uncertainty range.

RCP8.5: CanESM2: Canadian Earth System Model 2 is the second generation of Earth System Model developed by the Canadian Centre for Climate Modelling and Analysis (CCCma). It is a section of the Climate Research Division which develops and applies computer models of the climate system to simulate global and Canadian climate, and to predict changes on seasonal to centennial timescales. Analysis of these simulations, together with observations, is used to provide science-based quantitative information to inform climate change adaptation and mitigation in Canada and internationally, and to improve our understanding of the climate system. Notably, CCCma develops the modelling system used to produce seasonal forecasts operationally by Environment and Climate Change Canada, and carries out climate model experiments coordinated by the World Climate Research Programme (WCRP) in support of the Intergovernmental Panel on Climate Change (IPCC). Read More | Download link

CSIRO_Mk3: The Commonwealth Scientific and Industrial Research Organization Mark 3 (CSIRO_Mk3) climate system model contains a comprehensive representation of the four major components of the climate system (atmosphere, land surface, oceans and sea-ice. It is a coupled atmosphere-ocean system that gives a significantly improved representation of the current climate relative to the prior model generations. It was also highly desirable that this be achieved without the need for any artificial corrections (the so called “flux adjustments”) to the flux quantities connecting the atmospheric and oceanic systems. This has been successfully achieved with the Mk3 climate system model. The Mk3 model will be used to investigate the dynamical and physical processes controlling the climate system, for multiseasonal predictions, and for investigations of natural climatic variability and climatic change. Read More | Download link

GFDL_ESM2G: The Geophysical Fluid Dynamics Laboratory (GFDL) developed NOAA’s first Earth System Models (ESMs) to advance our understanding of how the Earth’s biogeochemical cycles, including human actions, interact with the climate system. Like GFDL’s physical climate models, these simulation tools are based on an atmospheric circulation model coupled with an oceanic circulation model, with representations of land, sea ice and iceberg dynamics. ESMs incorporate interactive biogeochemistry, including the carbon cycle. GFDL produced two new models representing ocean physics with alternative numerical frameworks to explore the implications of some of the fundamental assumptions embedded in these models. The models differ mainly in the physical ocean component. In one model, ESM2M, pressure-based vertical coordinates are used along the developmental path of GFDL’s Modular Ocean Model version 4.1. In the other, ESM2G, an independently developed isopycnal model using the Generalized Ocean Layer Dynamics (GOLD) code base was used. Read More | Download link

IPSL-CM5A: IPSL-CM5A is an Earth system model based on an improved version of the IPSL-CM4 coupled ocean-atmosphere GCM that was used in CMIP3. Compared with IPSL-CM4, IPSL-CM5A includes among others the following improvements: (i) An increase vertical resolution of the atmosphere from 19 to 39 vertical levels, with 15 levels above 20 km (ii) six different species of aerosols that can be either externally prescribed or computed on-line (iii) stratospheric and tropospheric ozone can be either prescribed or computed on-line (iv) improved physical parameterizations of the ocean (v) carbon cycle models for both the ocean part and terrestrial part and land use change can be externally imposed. IPSL-CM5A is one of the two configurations of the IPSL-CM5 model for CMIP5, the second one being IPSL-CM5B, with a different set of atmospheric physical parameterizations. IPSL-CM5 is developed by IPSL, includes 5 component models representing the Earth System climate and its carbon cycle: LMDz (atmosphere), NEMO (ocean, oceanic biogeochemistry and sea-ice), ORCHIDEE (continental surfaces and vegetation), and INCA (atmospheric chemistry), coupled through OASIS. IPSL modelling system also includes an I/O library (IOIPSL), an assembling and compiling environment (modipsl), an execution environment (libIGCM) and a set of post-processing tools. IPSLESM, available in different configurations at different resolutions, is in permanent evolution to reflect state-of-the-art numerical climate science. Read More | Download link